jQuery.extend({
    //handleError: function (s, xhr, status, e) {
    //    // If a local callback was specified, fire it
    //    if (s.error) {
    //        s.error.call(s.context || s, xhr, status, e);
    //    }

    //    // Fire the global callback
    //    if (s.global) {
    //        (s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
    //    }
    //},
    createUploadIframe: function (id, uri) {
        //create frame
        var frameId = 'jUploadFrame' + id;
        var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
        if (window.ActiveXObject) {
            if (typeof uri == 'boolean') {
                iframeHtml += ' src="' + 'javascript:false' + '"';

            } else if (typeof uri == 'string') {
                iframeHtml += ' src="' + uri + '"';

            }
        }
        iframeHtml += ' />';
        jQuery(iframeHtml).appendTo(document.body);

        return jQuery('#' + frameId).get(0);
    },
    createUploadForm: function (id, fileElementId, data) {
        //create form	
        var formId = 'jUploadForm' + id;
        var fileId = 'jUploadFile' + id;
        var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
        if (data) {
            for (var i in data) {
                jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
            }
        }
        var oldElement = jQuery('#' + fileElementId);
        var newElement = jQuery(oldElement).clone();
        jQuery(oldElement).attr('id', fileId);
        jQuery(oldElement).before(newElement);
        jQuery(oldElement).appendTo(form);

        //set attributes
        jQuery(form).css('position', 'absolute');
        jQuery(form).css('top', '-1200px');
        jQuery(form).css('left', '-1200px');
        jQuery(form).appendTo('body');
        return form;
    },

    ajaxFileUpload: function (s) {
        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout		
        s = jQuery.extend({},
        jQuery.ajaxSettings, s);
        var id = new Date().getTime();
        var form = jQuery.createUploadForm(id, s.fileElementId, (typeof (s.data) == 'undefined' ? false : s.data));
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;
        // Watch for a new set of requests
        if (s.global && !jQuery.active++) {
            jQuery.event.trigger("ajaxStart");
        }
        var requestDone = false;
        // Create the request object
        var xml = {}
        if (s.global) jQuery.event.trigger("ajaxSend", [xml, s]);
        // Wait for a response to come back
        var uploadCallback = function (isTimeout) {
            var io = document.getElementById(frameId);

            if (io.contentWindow) {
                xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML : null;
                xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument : io.contentWindow.document;

            } else if (io.contentDocument) {
                xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML : null;
                xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument : io.contentDocument.document;
            }

            if (xml || isTimeout == "timeout") {

                requestDone = true;
                var status;

                status = isTimeout != "timeout" ? "success" : "error";

                // Make sure that the request was successful or notmodified
                if (status != "error") {

                    // process the data (runs the xml through httpData regardless of callback)
                    var data = jQuery.uploadHttpData(xml, s.dataType);

                    console.log(s.success);
                    // If a local callback was specified, fire it and pass it the data
                    if (s.success) {

                        s.success(data, status);

                    }

                    // Fire the global callback
                    if (s.global) jQuery.event.trigger("ajaxSuccess", [xml, s]);
                } else jQuery.handleError(s, xml, status);

                // The request was completed
                if (s.global) jQuery.event.trigger("ajaxComplete", [xml, s]);

                // Handle the global AJAX counter
                if (s.global && !--jQuery.active) jQuery.event.trigger("ajaxStop");

                // Process result
                if (s.complete) s.complete(xml, status);

                jQuery(io).unbind()

                setTimeout(function () {
                    try {
                        jQuery(io).remove();
                        jQuery(form).remove();

                    } catch (e) {
                        jQuery.handleError(s, xml, null, e);
                    }

                },
                100)

                xml = null

            }
        }
        // Timeout checker
        if (s.timeout > 0) {
            setTimeout(function () {
                // Check to see if the request is still happening
                if (!requestDone) uploadCallback("timeout");
            },
            s.timeout);
        }

        var form = jQuery('#' + formId);
        jQuery(form).attr('action', s.url);
        jQuery(form).attr('method', 'POST');
        jQuery(form).attr('target', frameId);
        if (form.encoding) {
            jQuery(form).attr('encoding', 'multipart/form-data');
        } else {
            jQuery(form).attr('enctype', 'multipart/form-data');
        }
        jQuery(form).submit();

        jQuery('#' + frameId).load(uploadCallback);
        return {
            abort: function () { }
        };

    },

    uploadHttpData: function (r, type) {

        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        // If the type is "script", eval it in global context
        if (type == "script") jQuery.globalEval(data);
        // Get the JavaScript object, if JSON is used.
        if (type == "json") return r;
        // evaluate scripts within html
        if (type == "html") jQuery("<div>").html(data).evalScripts();

        return r;
    }
})